Evaluation of a Siliorane System for Use in Stabilization of Traumatic Bone Injuries

Current methods for preparing battlefield and domestic trauma extremity fractures for transport to medical facilities are inadequate.

These methods are unable to stabilize severe, comminuted fractures and to limit wound access and drainage.

The overall aim of this study was to create a silorane based composite providing an alternative approach to stabilizing traumatic extremity fractures.

The intended application of this material is to provide temporary stabilization of fractured bones by wrapping a composite around the bone fragments.

After the patient has reached an adequate surgical facility, the stabilizing material will be removed.

In this study, a silorane polymer was modified through the addition of various types and quantities of fillers to create a biocompatible composite for the proposed bone stabilization application.

Fracture stability is a complex characteristic that entails many physical and biological properties promoting successful healing.

For this study, stability was assessed as the ability of a stabilized bone to resist a bending movement as measured through flexural strength.

Using these measures, the optimal silorane composite formulation was identified for the application of bone stabilization.

Three different fillers were explored: an yttria alumino-silicate glass, a barium boroaluminosilicate glass, and alumina nanorods.

The filler formulations that provided the best mechanical properties were estimated through a design of experiments mixture design scheme.

Initial tests were completed using a photoinitiated silorane resin.

Chemical and mixed initiator systems were also explored, but currently none were identified with properties superior to photoinitiated composites.

Four optimal photoinitiated composites were tested for cytotoxicity.

The composite formulation that provided the best properties, containing 45wt% M12 glass and 5wt% alumina nanorod fillers in photoinitiated silorane resin, was then used to stabilize fractured mouse femora both ex vivo and in vivo.

Further testing of this material is required to fully characterize the effects of the composite on fracture healing and to develop a chemical initiation system for the composite.

Further optimization of the formulation will be possible based on the results of these studies.